CHARACTERIZING PALEOCLIMATIC DATA USING PUERTO RICAN STALAGMITES AS ARCHIVES

Current archaeological evidence shows human activity in Puerto Rico exceeding ~5,000 years ago with context such as settlement patterns and agricultural practices, especially surrounding karst geology. Karst features like caves, sinkholes, and hills among others, were used as a central theme for many social and ceremonial interactions by the Arawak-Taíno people who originally settled the Caribbean region. Relationships between karst and local communities in the Caribbean continue today through place names and community practices. Specific dates of pictography from Cueva Maria Soto in the karstic municipality of Arecibo, Puerto Rico suggest human activity in and around the cave from ~3,720 years ago to the present. However, this archaeological data lacks environmental context. Knowledge about past precipitation and vegetation of the region could be used to contextualize archaeological evidence such as possible abandonments among other settlement changes. A 31.9 cm stalagmite (MS1) retrieved from Cueva Maria Soto was slabbed and subsampled in 1.5 mm increments, along the central growth axis, using a CNC gravity mill producing 205 subsamples. In this ongoing study we will be analyzing stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotopes along with accelerator mass spectrometry, laser ablation, and acid digestion trace element analysis. This study is expected to yield information that can provide paleoenvironmental and hydroclimate context to current archaeological data and support current efforts to develop a scientific narrative that is localized, and place based. We will discuss our latest results of this interdisciplinary and multiproxy study during the GSA’s SE meeting.